Control of plasma sheath with bias supplies
AssigneeAdvanced Energy Industries, Inc.
InventorsDenis Shaw, Kevin Fairbairn, Daniel Carter
Life of this patent
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Abstract
Systems and methods for plasma processing are disclosed. An exemplary system may include a plasma processing chamber including a source to produce a plasma in the processing chamber and at least two bias electrodes arranged within the plasma processing chamber to control plasma sheaths proximate to the bias electrodes. A chuck is disposed to support a substrate, and a source generator is coupled to the plasma electrode. At least one bias supply is coupled to the at least two bias electrodes, and a controller is included to control the at least one bias supply to control the plasma sheaths proximate to the bias electrodes.
Claims20
A system for plasma processing, the system comprising:
- a processing chamber comprising a first electrical plane and a second electrical plane;
- a first bias supply to provide a first asymmetric periodic voltage waveform to the first electrical plane;
- a second bias supply to provide a second asymmetric periodic voltage waveform to the second electrical plane;
- a controller to receive an indication of ion current proximate to the first electrical plane and receive an indication of ion current proximate to the second electrical plane and control, based upon the indications of ion current, at least the second bias supply.
A method for processing a substrate in a plasma processing chamber, the method comprising:
- producing a plasma in the plasma processing chamber;
- applying a first asymmetric periodic voltage waveform to an inner zone in the plasma processing chamber with a first bias supply;
- and
- applying a second asymmetric periodic voltage waveform to an outer zone in the plasma processing chamber with a second bias supply;
- and
- adjusting, based upon ion current measurements proximate to the inner zone and the outer zone in the plasma processing chamber, one or more characteristics of the asymmetric periodic voltage waveforms to alter corresponding portions of a plasma sheath.
A non-transitory computer-readable medium comprising instructions stored thereon, for execution by a processor, or for configuring a field programmable gate array, to perform plasma processing, the instructions including instructions to:
- control a plurality of bias supplies to apply an asymmetric periodic voltage waveform to each of a plurality of zones in the plasma processing chamber;
- and
- control one or more of the plurality of bias supplies to adjust, based upon ion current measurements proximate to the plurality of zones in the plasma processing chamber one or more characteristics of the asymmetric periodic voltage waveforms to alter corresponding portions of a plasma sheath.
Dependencies are inferred from the claim text.